陳蕙雅思教材 - 雅思閱讀精選 (The Source of Energy)

The Source of Energy

A summary of the physicaland chemical nature of life must begin, not on

the Earth, but in theSun; in fact, at the Sun's very center. It is here

that is to be found thesource of the energy that the Sun constantly pours

out into         space as light and heat. This energy isliberated at the center of

the Sun as billions uponbillions of nuclei of     hydrogen atomscollide with

each other and fusetogether to form nuclei of helium, and in doing so,

release some of theenergy that is stored in the nuclei of atoms. The

output of light and heatof the Sun requires that some 600                milliontons of

hydrogen be  converted into  helium in the Sun every second.  This the Sun

has  been doing for several      thousands  of millions of years.  The nuclear

energy is released at the Sun's center ashigh-energy  gamma radiation, a

form of electromagnetic     radiation like  light and radio waves, only of very

much shorter wavelength.This gamma radiation is absorbed by       atomsinside

the Sun to be reemittedat slightly longer wavelengths. This radiation, in

its turn is  absorbed and reemitted. As the energy filters through the

layers of the solar interior,it passes through the X-ray part of the    

spectrum eventuallybecoming light. At this stage, it has reached what we

call the solar surface,and can escape       into space withoutbeing absorbed

further by solar atoms. Avery small  fraction  of  the Sun's light  and  

heat  is   emitted  in  such directions  that  after passing unhindered

through interplanetaryspace, it hits the Earth.

能量的來源

概說生命的物理和化學特性必須始於太陽--確切地說，是太陽的核心，而非地球。  能 量來自太陽的核心。

在這裡，太陽不停地以光和熱的形式向空間傾瀉出能量。 數十億計的 氫原子核在太陽的核心碰撞並且聚變生成氦。  在此過程中一部分原本儲存於原子核中的能

量被釋放出來。 太陽所產生的光和熱需要每秒將六億噸氫轉化為氦。 這樣的轉化在太陽中

已經持續幾十億年了。  核能在太陽的核心被釋放為高能的伽馬射線。  這是一種電磁射線， 就象光波和無線電波一樣，只是波長要短得多。  

這種伽瑪射線被太陽內的原子所吸收，然 後重新釋放為波長稍長一些的光波。 這新的射線再次被吸收，而後釋放。 在能量由太陽內

部一層層滲透出來的過程中，它經過了光譜中 X 射線部分，最後變成了光。  在此階段，能

量到達我們所稱的太陽表層，並且離散到空間而不再被太陽原子所吸收。  只有很小一部分 太陽的光和熱由此方向釋放出來，並且未被阻擋，穿越星空，來到地球。